Display device and method of manfuacturing the same

ABSTRACT

Disclosed is a display device including: a substrate including a plurality of first pads transmitting a gate signal, a plurality of second pads transmitting a data signal, a plurality of third pads transmitting a first power voltage, and a plurality of fourth pads transmitting a second power voltage different from the first power voltage within a display area; and a plurality of display modules, each of which includes a light emitting diode connected to first to fourth electrodes attached to the first to fourth pads, a first transistor connected to the first electrode and the second electrode, a second transistor connected to the third electrode, and a light emitting diode connected to the second transistor and the fourth electrode.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2021-0167506 filed in the Korean IntellectualProperty Office on Nov. 29, 2021, the entire contents of which areincorporated herein by reference.

BACKGROUND (A) Field

An exemplary embodiment relates to a display device and a method ofmanufacturing the display device.

(B) Description of the Related Art

Recently, a Light Emitting Diode (LED) display device using an LED as alight emitting element has been developed. In the LED display device, asmall LED (mini LED and micro LED) may be used. The LED display devicehas a large advantage in terms of power consumption reduction andminiaturization.

In the meantime, a transparent display device using the LED displaydevice may be applied in various fields because an object or an imagelocated at the rear of the display device can pass the display deviceand be recognized by a user located in front of the display device.

The above information disclosed in this Background section is only forenhancement of understanding of the background, and therefore it maycontain information that does not form the prior art that is alreadyknown in this country to a person of ordinary skill in the art.

SUMMARY

The present invention has been made in an effort to provide a displaydevice with higher transmittance.

The present invention has also been made in an effort to provide adisplay device in which a display module is easily bonded with asubstrate.

An exemplary embodiment of the present invention provides a displaydevice including: a substrate including a plurality of first padstransmitting a gate signal, a plurality of second pads transmitting adata signal, a plurality of third pads transmitting a first powervoltage, and a plurality of fourth pads transmitting a second powervoltage different from the first power voltage within a display area;and a plurality of display modules, each of which includes first tofourth bonding electrodes attached to the first to fourth pads, a firsttransistor connected to the first bonding electrode and the secondbonding electrode, a second transistor connected to the third bondingelectrode, and a light emitting diode connected to the second transistorand the fourth bonding electrode.

The substrate further includes a plurality of gate lines and a pluralityof second power voltage lines extended in a first direction and arrangedin a second direction crossing the first direction, and a plurality ofdata lines and a plurality of first power voltage lines extended in thesecond direction and arranged in the first direction, and the pluralityof first pads is connected to the plurality of gate lines, the pluralityof second pads is connected to the plurality of data lines, theplurality of third pads is connected to the plurality of first powervoltage lines, and the plurality of fourth pads is connected to theplurality of second power voltage lines.

The plurality of display modules is arranged in a matrix form in thefirst direction and the second direction, and at least one of theplurality of display modules is arranged to be shifted in a columndirection or a row direction.

At least one of the plurality of display modules connected to the firstdata line among the plurality of data lines is connected to a firstpower voltage line different from first power voltage lines of otherdisplay modules.

At least one of the plurality of display modules connected to a firstgate line among the plurality of gate lines is connected to a secondpower voltage line different from second power voltage lines of otherdisplay modules.

The plurality of display modules includes a plurality of first displaymodules each of which includes a plurality of light emitting diodes, anda plurality of second display modules each of which includes one lightemitting diode.

In the plurality of first display modules, the plurality of lightemitting diodes is arranged in different forms.

The plurality of gate lines and the plurality of second power voltagelines, and the plurality of data lines and the plurality of first powervoltage lines are located on different layers.

The display area has a non-quadrangular form.

The substrate has a curved form.

The substrate includes at least one of a front glass, a rear glass, andside mirrors of a vehicle.

The display device further includes a curved glass substrate, and thesubstrate is flexible and is attached to the glass substrate.

The glass substrate may include at least one of a front glass, a rearglass, and side mirrors of a vehicle.

The display device may further include a gate driving unit supplying thegate signal and a source driving unit supplying the data signal, thegate driving unit and the source driving unit being disposed in a bezelarea.

Each of the plurality of display modules further includes: a displayelement including a substrate, a first conductive semiconductor layer onthe substrate, a first electrode on the first conductive semiconductorlayer, a first activation layer on the first conductive semiconductorlayer, a second conductive semiconductor layer on the first activationlayer, a reflective layer on the second conductive semiconductor layer,a first passivation layer covering the reflective layer, a firstelectrode connected to the first conductive semiconductor layer andlocated on the first passivation layer, and a second electrode connectedto the reflective layer and located on the passivation layer, in whichthe light emitting diode includes the first conductive semiconductorlayer, the first activation layer, and the second conductivesemiconductor layer; and a transistor including a first gate electrodeon the first passivation layer, a gate insulating layer on the firstgate electrode, a second activation layer on the gate insulating layer,a source electrode and a drain electrode on the second activation layer,a second passivation layer covering the source electrode and the drainelectrode, and a second gate electrode on the second passivation layer,and the first bonding electrode is connected to the first electrode, thesecond bonding electrode is connected to the drain electrode, and thesecond electrode is connected to the source electrode.

Another exemplary embodiment of the present invention provides a displaydevice including: a display element including a substrate, a firstconductive semiconductor layer on the substrate, a first electrode onthe first conductive semiconductor layer, a first activation layer onthe first conductive semiconductor layer, a second conductivesemiconductor layer on the first activation layer, a reflective layer onthe second conductive semiconductor layer, a first passivation layercovering the reflective layer, a first electrode connected to the firstconductive semiconductor layer and located on the first passivationlayer, and a second electrode connected to the reflective layer andlocated on the passivation layer, a transistor including a first gateelectrode on the first passivation layer, a gate insulating layer on thefirst gate electrode, a second activation layer on the gate insulatinglayer, a source electrode and a drain electrode on the second activationlayer, a second passivation layer covering the source electrode and thedrain electrode, and a second gate electrode on the second passivationlayer; and a first bonding electrode connected to the first electrodeand a second bonding electrode connected to the drain electrode, inwhich the second electrode is connected to the source electrode.

The first conductive semiconductor layer and the second conductivesemiconductor layer may be formed of an III-V group material.

The first activation layer may be formed of an III-V group material.

At least one of the first electrode, the second electrode, the firstgate electrode, the source electrode, the drain electrode, the secondgate electrode, the first bonding electrode, and the second bondingelectrode may include at least one transparent material of an indium tinoxide (ITO), an indium zinc oxide (IZO), and an Ag nanowire.

Another exemplary embodiment of the present invention provides a methodof manufacturing a display device, the method including: forming a firstconductive semiconductor layer on a substrate; forming a firstactivation layer on the first conductive semiconductor layer; forming asecond conductive semiconductor layer on the first activation layer;forming a light emitting diode by forming a reflective layer on thesecond conductive semiconductor layer; forming a first passivation layercovering the reflective layer; forming a first electrode connected tothe first conductive semiconductor layer on the first passivation layerand a second electrode and a first gate electrode connected to thereflective layer; forming a gate insulating layer on the first gateelectrode; forming a second activation layer on the gate insulatinglayer; forming a drain electrode and a source electrode connected to thesecond electrode on the second activation layer; forming a secondpassivation layer covering the source electrode and the drain electrode;forming a transistor by forming a second gate electrode on the secondpassivation layer; forming a third passivation layer on the second gateelectrode; forming a first bonding electrode connected to the firstelectrode and a second bonding electrode connected to the drainelectrode on the third passivation layer; cutting the substrate on whichthe light emitting diode and the transistor are formed into a pluralityof display modules; and attaching the display module to the substrateincluding a plurality of pads to which a signal used for the lightemitting diode to emit light is applied.

According to the exemplary embodiments, the effects of the displaydevice and the method of manufacturing the display device are asfollows.

According to at least one of the exemplary embodiments, there is anadvantage in that it is possible to provide a more transparent displaydevice.

Further, according to at least one of the exemplary embodiments, thereis an advantage in that it is possible to decrease a possibility ofdamage of a bonding portion between a substrate and a display module ofa display device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically illustrating a display deviceaccording to an exemplary embodiment.

FIG. 2 is a circuit diagram illustrating an example of a display elementof the display device according to an exemplary embodiment.

FIG. 3 is a top plan view illustrating a substrate of the display deviceaccording to the exemplary embodiment.

FIG. 4 is a cross-sectional view of a partial region of the displaydevice in which a display module is bonded to the substrate of FIG. 3 .

FIGS. 5 to 7 are cross-sectional views of the display modulemanufactured according to a method of manufacturing a display deviceaccording to an exemplary embodiment.

FIGS. 8 to 10 are top plan views illustrating the display deviceaccording to various aspects of the exemplary embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will bedescribed with reference to accompanying drawings so as to be easilyunderstood by a person ordinary skilled in the art. However, the presentinvention can be variously implemented and is not limited to thefollowing exemplary embodiments.

In addition, the size and thickness of each configuration shown in thedrawings are arbitrarily shown for understanding and ease ofdescription, but the present invention is not limited thereto.

Further in the drawings, the thickness of layers, films, panels,regions, etc., are exaggerated for clarity. In the drawings, forunderstanding and ease of description, the thickness of some layers andareas is exaggerated. It will be understood that when an element such asa layer, film, region, or substrate is referred to as being “on” anotherelement, it can be directly on the other element or intervening elementsmay also be present.

In addition, unless explicitly described to the contrary, the word“comprise”, and variations such as “comprises” or “comprising”, will beunderstood to imply the inclusion of stated elements but not theexclusion of any other elements. Further, in the specification, the word“on” means positioning on or below the object portion, but does notessentially mean positioning on the upper side of the object portionbased on a gravity direction.

Hereinafter, a display device according to an exemplary embodiment willbe described with reference to FIG. 1 .

FIG. 1 is a block diagram schematically illustrating a display deviceaccording to an exemplary embodiment. As illustrated in FIG. 1 , thedisplay device 10 includes a plurality of display modules 100 a, 100 b,100 c, ..., and 100 z, a substrate 200 on which the plurality of displaymodules 100 a, 100 b, 100 c, ..., and 100 z are located, and drivingunits 300 and 400 providing signals corresponding to the plurality ofdisplay modules 100 a, 100 b, 100 c, ..., and 100 z.

Each display module 100 includes a display element emitting lightaccording to the signals of the driving units 300 and 400. One displaymodule 100 may have one display element or a plurality of displayelements emitting light of one color wavelength.

The signals from the driving units 300 and 400 may be transmitted toeach display module 100 through a plurality of bonding electrodes 110 a,111 a, 112 a, and 113 a of each display module 100. The plurality ofbonding electrodes 110 a, 111 a, 112 a, and 113 a is electricallyconnected with a bonding pad on the substrate 200.

The number of plurality of bonding electrodes 110 a, 111 a, 112 a, and113 a is different depending on the number of display elements includedin each display module 100. For example, four types of signals (forexample, a gate signal, a data signal, a first power voltage, and asecond power voltage) are applied to one display element, the displaymodule 100 including one display element may have fourth bondingelectrodes, and the display module 100 including four display elementsmay have 16 bonding electrodes. The plurality of bonding electrodes 110a, 111 a, 112 a, and 113 a may be formed of a transparent material.

The display module 100 including the plurality of display elements mayalso include a common bonding electrode receiving a signal commonlyapplied to each display element. For example, the display module 100including four display elements in the form of 1 × 4 may include sevenbonding electrodes (four data signal bonding electrodes, one gate signalbonding electrode, one first power voltage bonding electrode, and onesecond power voltage bonding electrode).

The substrate 200 includes a plurality of signal lines. For example, thesubstrate 200 includes a plurality of gate lines G1, G2, ..., and Gn,and a plurality of data lines D1, D2, ..., and Dm. Further, thesubstrate 200 includes power voltage lines VDD and VSS providing thepower voltage. The plurality of signals lines may be located ondifferent layers or located on the same layer on the substrate 200.

The plurality of data lines D1, D2, ..., and Dm is extended in asubstantially column direction and is almost parallel to each other. Theplurality of gate lines G1, G2, ..., and Gn is extended in asubstantially row direction and is almost parallel to each other.

A bonding pad on the substrate 200 may be located on a surface of thesubstrate 200. The disposition forms of the bonding pads connected toone display element on the substrate 200 are the same. The bonding padon the substrate 200 is electrically connected with the plurality ofsignal lines.

A gate driving unit 300 is connected with each display module 100through the plurality of gate lines G1, G2, ..., and Gn. The gatedriving unit 300 generates the plurality of gate signals according tothe control signal and transmits the generated gate signal to thecorresponding gate line among the plurality of gate lines.

A source driving unit 400 is connected with each display module 100through the plurality of data lines D1, D2, ..., and Dm. The sourcedriving unit 400 receives an image data signal, a control signal, andthe like and transmits a data signal to the corresponding data lineamong the plurality of data lines D1, D2, ..., and Dm. The sourcedriving unit 400 selects a grayscale voltage according to the image datasignal and transmits the selected grayscale signal to the plurality ofdata lines as the data signal.

The source driving unit 400 samples and holds the image data signal, andtransmits the plurality of data signals to the plurality of data linesD1, D2, ..., and Dm, respectively. For example, the source driving unit400 may apply a data signal having a predetermined voltage range to theplurality of data lines D1, D2, ..., and Dm in response to the gatesignal of an enable level.

In addition to this, the gate driving unit 300 and/or the source drivingunit 400 apply the first power voltage and the second power voltage tothe power voltage lines VDD and VSS. The first power voltage applied toa power voltage line VDD and the second power voltage applied to thepower voltage line VSS may have different values.

The substrate 200, the signal lines G1, G2, ..., Gn, D1, D2, ..., Dm,VDD, and VSS, and the pads 110 a, 111 a, 112 a, and 113 a on thesubstrate are formed of the transparent material and the transparentelectrode is also used in the display module 100, thereby implementingthe display device 100 with high transmittance.

In the meantime, when the substrate 200 has stretchable, flexible,bendable, and foldable properties, a curved display with hightransmittance may be implemented by mounting the display module 100 tothe substrate 200. Otherwise, a curved display with high transmittancemay also be implemented by mounting the display module 100 to thesubstrate 200 and then attaching the substrate 200 to a curved glasssubstrate and the like in a specific form. The curved display may beused as a front glass, a rear glass, and a side mirror of a vehicle,glass of a building, and a mirror.

Next, the display element included in the display module 100 will bedescribed with reference to FIG. 2 .

FIG. 2 is a circuit diagram illustrating an example of a display deviceof the display element according to an exemplary embodiment. The displayelement will be described based on a display module 100 a as an example.

Referring to FIG. 2 , the display element includes a first transistorT1, a second transistor T2, a storage capacitor C1, and a light emittingdiode LED.

A gate of the first transistor T1 is connected with the first gate lineG1 through the bonding electrode 110 a, one end of the first transistorT1 is connected with the data line D1 through the bonding electrode 111a, and the other end of the first transistor T1 is connected to a gateof the first transistor T1 at a first node N1.

The first transistor T1 is turned on according to the gate signalreceived through the gate line G1 and performs a switching operation oftransmitting the data signal transmitted to the data line D1 to thefirst node N1.

A gate of the second transistor T2 is connected to one electrode of astorage capacitor C1 at the first node N1, one end of the secondtransistor T2 is connected with the power voltage line VDD supplying thefirst power voltage through the bonding electrode 112 a, and the otherend of the second transistor T2 is electrically connected with an anodeof the light emitting diode LED. The second transistor T2 receives adata signal according to a switching operation of the first transistorT1 and supplies a driving current to the light emitting diode LED.

The other electrode of the storage capacitor C1 is connected with thepower voltage line VDD through a bonding electrode 113 a.

A cathode of the light emitting diode LED is connected with the powervoltage line VSS. The light emitting diode LED receives a drivingcurrent from the second transistor T2 and emits light.

Next, the substrate 200 on which the display module 100 is disposed willbe described with reference to FIG. 3 .

FIG. 3 is a top plan view illustrating the substrate of the displaydevice according to the exemplary embodiment.

On the substrate 200, a gate line 210 and a power voltage line 213extended in a first direction (x-axis direction) are arranged in asecond direction (y-axis direction), and a data line 211 and a powervoltage line 212 extended in the second direction (y-axis direction) arearranged in the first direction (x-axis direction).

The gate line 210 and the power voltage line 213 may be located on thedifferent layer from that of the data line 211 and the power voltageline 212.

The form of the disposition of the pads 210 c, 211 c, 212 c, and 213 ccorresponding to one display element may be the same on the substrate200. Each of the pads 210 c, 211 c, 212 c, and 213 c is connected to asignal line corresponding to the plurality of signal lines 210 a, 211 a,212 a, and 213 a through corresponding one among connection wires 210 b,211 b, 212 b, and 213 b.

Next, a structure of the display device will be described with referenceto FIG. 4 .

FIG. 4 is a cross-sectional view of a partial region of the displaydevice in which the display module is bonded to the substrate of FIG. 3.

Referring to FIG. 4 , the display module 100 is located on the substrate200. The bonding electrodes 112 a and 113 a of the display module 100are electrically connected to the pads 212 c and 213 c of the substrate200.

The display element 120 may be located on a module substrate 101. Inthis case, the module substrate 101 may be selected from the groupconsisting of sapphire, silicon carbide, zinc oxide, gallium nitride,aluminum nitride, zirconium diboride, gallium arsenide, and silicon, butis not limited thereto.

In particular, other than sapphire, other heterogeneous substrates, suchas glass, silicon carbide, silicon, GaAs, GaP, AlGalNP, Ge, SiSe, GaN,AlInGaN, and InGaN, may be used.

A transistor 130 is located on the module substrate 101. The displayelement 120 is connected with the transistor 130 (the second transistorT2 of FIG. 2 ). For example, an electrode 126 of the display element 120is connected with an electrode 135 of the transistor 130.

The transistor 130 according to the exemplary embodiment of the presentinvention may be configured with any one of a coplanar structure, astaggered structure, an inverted coplanar structure, and an invertedstaggered structure.

The display element 120 includes a first conductive semiconductor layer121, a first electrode 125, a first activation layer 122, a secondconductive semiconductor layer 123, a second electrode 126, and a firstpassivation layer 127.

More particularly, the first conductive semiconductor layer 121 islocated on the module substrate 101. The first activation layer 122 islocated on the first conductive semiconductor layer 121, and the secondconductive semiconductor layer 123 is located on the first activationlayer 122.

In this case, the first activation layer 122 may have a quantum wellstructure, such as GaN, InGaN, AlGaN, GaP, AlGaInP, AllnP, InP, GaAs,InGaAs, and AlGaAs, and may be formed of a III-V group material.

The first conductive semiconductor layer 121 and the second conductivesemiconductor layer 123 may include a p-GaN-based semiconductor materialor an n-GaN-based semiconductor material, but the materials of the firstactivation layer 122 and the semiconductor layers 121 and 123 are notlimited thereto. The n-GaN-based semiconductor material may include aIII-V group material, such as GaN, n-GaN, n-InGaN, n-AlGaN, n-GaP,n-AlGaInP, n-AlInP, n-InP, n-GaAs, n-InGaAs, and n-AlGaAs. When thefirst conductive semiconductor layer 121 includes an n-GaN-basedsemiconductor material, impurities used for doping the first conductivesemiconductor layer 121 include Si, Ge, Se, Te, or C. The p-GaN-basedsemiconductor material may include an III-V group material, such as GaN,p-GaN, p-InGaN, p-AlGaN, p-GaP, p-AlGaInP, p-AlInP, p-InP, p-GaAs,p-InGaAs, and p-AlGaAs. Herein when the second conductive semiconductorlayer 123 includes the p-GaN-based semiconductor material, impuritiesused for doping the second conductive semiconductor layer 123 includesMg, Zn, or Be.

A reflective layer 124 is located on the second conductive semiconductorlayer 123. Therefore, the display module 100 emits light in directionA1.

A first passivation layer 127 is located on the reflective layer 124.The first electrode 125 is connected to the first conductivesemiconductor layer 121 through a contact hole, and the second electrode126 is connected to the reflective layer 124 through a contact hole. Thefirst electrode 125 and the second electrode 126 may include atransparent material including at least one of an indium tin oxide(ITO), an indium zinc oxide (IZO), and an Ag nanowire.

In the meantime, the transistor 130 is formed of a first gate electrode131, a gate insulating layer 132, a second activation layer 133, asource electrode 134, a drain electrode 135, a second passivation layer136, and a second gate electrode 137. The transistor 130 is a dual gatetransistor, and may decrease a leakage current flowing through thetransistor 130.

In particular, the first gate electrode 131 is located on the firstpassivation layer 127. The gate insulating layer 132 is located on thefirst gate electrode 131, the second activation layer 133 is located onthe gate insulating layer 132, and the drain electrode 135 and thesource electrode 134 are located on the second activation layer 133. Thefirst gate electrode 131, the drain electrode 135, and the sourceelectrode 134 may be formed of a transparent material including at leastone of an ITO, an IZO, and an Ag nanowire.

The second activation layer 133 may include at least one of amorphoussilicon, polycrystalline silicon, and a semiconductor oxide.

Further, the second electrode 126 of the display element 120 and thedrain electrode 135 of the transistor 130 are electrically connected,and may be formed of the same material.

The second passivation layer 136 is located on the second activationlayer 133, the source electrode 134, and the drain electrode 135, andthe second gate electrode 137 is located on the second passivation layer136. The second gate electrode 137 may be formed of a transparentmaterial including at least one of an ITO, an IZO, and an Ag nanowire.

A third passivation layer 102 is formed on the transistor 130 configuredas described above, to protect the transistor 130.

The bonding electrode 113 a and the bonding electrode 112 a are locatedon the third passivation layer 102. The bonding electrode 113 a isconnected to the first electrode 125 through the contact hole, and thebonding electrode 112 a is connected to the source electrode 134 of thetransistor 130 through the contact hole. The bonding electrodes 112 aand 113 a may be formed of a transparent material including at least oneof an ITO or an IZO and an Ag nanowire.

The substrate 200 includes a first substrate layer 201, the data line211 and the power voltage line 212 located on the first substrate layer201, a second substrate layer 202 located on the data line 211 and thepower voltage line 212, the gate line (not illustrated) and the powervoltage line 213 located on the second substrate layer 202, a thirdsubstrate layer 203 located on the gate line (not illustrated) and thepower voltage line 213, and pads 212 c and 213 c located on the thirdsubstrate layer 203 and connected to the corresponding signal linethrough the contact hole.

Next, a method of manufacturing the display module 100 will be describedwith reference to FIGS. 5 to 7 .

FIGS. 5 to 7 are cross-sectional views of the display modulemanufactured according to a method of manufacturing a display deviceaccording to an exemplary embodiment.

As illustrated in FIG. 5 , a first conductive semiconductor layer 121, afirst activation layer 122, a second conductive semiconductor layer 123,and a reflective layer 124 are formed on a module substrate 101.

Thereafter, a first passivation layer 127 is formed on the firstconductive semiconductor layer 121, the first activation layer 122, thesecond conductive semiconductor layer 123, and the reflective layer 124.Then, an individual display element is formed by etching the layers 121,122, 123, and 124 formed on the module substrate 101.

Then, a first electrode 125 and a second electrode 126 are formed on thefirst passivation layer 127. The first electrode 125 is connected to thefirst conductive semiconductor layer 121 through a contact hole. Thesecond electrode 126 is connected to the reflective layer 124 throughthe contact hole.

Next, as illustrated in FIG. 6 , a transistor 130 is formed on a displayelement 120.

A first gate electrode 131 is formed on the first passivation layer 127.The first gate electrode 131 may be formed together with the firstelectrode 125 and the second electrode 126. A gate insulating layer 132is formed on the first gate electrode 131, the first electrode 125, andthe second electrode 126.

A second activation layer 133 is formed on the gate insulating layer132, and a drain electrode 135 and a source electrode 134 are formed ina drain region and a source region of the second activation layer 133,respectively. The drain electrode 135 of the transistor 130 is connectedwith the second electrode 126 of the display element 120 through thecontact hole.

A second passivation layer 136 is formed on the second activation layer133, the source electrode 134, and the drain electrode 135. A secondgate electrode 137 is formed on the second passivation layer 136.

A third passivation layer 102 is formed on the second passivation layer136 and the second gate electrode 137. The first to third passivationlayers 127, 136, and 102 may be formed of a single layer or multiplelayers of a silicon oxide (SiOx) or a silicon nitride (SiNx), but arenot limited thereto.

A bonding electrode 113 a and a bonding electrode 112 a are formed onthe third passivation layer 120. The bonding electrode 113 a isconnected to the first electrode 125 through the contact hole, and thebonding electrode 112 a is connected to the source electrode 134 of thetransistor 130 through the contact hole.

Referring to FIG. 7 , the transistor 130 is separated to display modules100-1 and 100-2 having at least one display element 120 by cutting thedisplay element 120 and the transistor 130 formed on the modulesubstrate 101 along a cutting line 140.

Next, a display device in which various forms of display modules aredisposed will be described with reference to FIGS. 8 to 10 .

FIGS. 8 to 10 are top plan views illustrating the display deviceaccording to various aspects of the exemplary embodiment.

As illustrated in FIG. 8 , a plurality of display modules 100 is locatedwithin a non-quadrangular display area DA. The display modules 100 arearranged in a matrix form. For example, the display modules 1000, 1001,and 1002 connected to the same gate line Gi are connected to the samepower voltage line VSS1. Similarly, the display modules 1002, 1004, and1005 connected to the same data line Dj+2 are connected to the samepower voltage line VDD3.

As illustrated in FIG. 9 , a plurality of display modules 100 is locatedwithin a non-quadrangular display area DA. The display modules 100 arearranged to be shifted in a column direction. For example, the displaymodules 1002, 1004, and 1005 connected to the same data line Dj+2 areconnected to the different power voltage line VDD2 or VDD3.

In addition to this, the display module 100 may also be arranged to beshifted in a row direction along the form of the display area DA. Thatis, the display module 100 may be freely attached to a pad located onthe substrate 200.

Comparing the dispositions of the display modules 100 of FIGS. 8 and 9 ,areas of the regions BA1 and BA2 in which the display modules 100 arenot disposed in FIG. 8 are larger than areas of the regions BA3 and BA4in which the display modules 100 are not disposed in FIG. 9 . Therefore,a bezel area in the non-quadrangular display area DA is viewed morewidely.

The display device according to the exemplary embodiment may provide abezelless display device by freely disposing the display modules 100.

Referring to FIG. 10 , the display modules 1000 a and 1000 b may includea plurality of display elements 120 a, ..., and 120 k. For example, thedisplay module 1000 a may have display elements 120 a, 120 b, and 120 carranged in series. The display module 1000 b may have display elements120 h, 120 i, 120 j, and 120 k arranged in a 2 × 2 form.

The display module 100 may be configured in various forms whileincluding various number of display elements, so that the display module100 may correspond to various forms and/or various sizes of the displayarea DA.

In the meantime, in FIG. 10 , it is described that one display module1000 a or 1000 b includes the plurality of display elements 120 a, ...,and 120 k, but various display modules may be coupled as one displaymodule so that one module includes the plurality of display elements.

The display device according to the exemplary embodiment uses anindividual display module chip, so that it is possible to implement alarge display with a size of several tens of meters, which cannot becurrently implemented in display devices using OLED display elements.

Further, it was possible to implement a flexible display device using asubminature LED only in a passive matrix display form, but when thedisplay module chip according to the present disclosure is used, it ispossible to implement a flexible active matrix display using asubminiature LED. By disposing the gate driving unit 300 and the sourcedriving unit 400 for driving the display device 10 in the bezel aroundthe display area DA, the display device according to the exemplaryembodiment may also be used in a front glass, a rear glass, and sidemirrors of a vehicle, a glass of a building, a mirror, and the like.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. On the contrary, it is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A display device, comprising: a substrateincluding a plurality of first pads transmitting a gate signal, aplurality of second pads transmitting a data signal, a plurality ofthird pads transmitting a first power voltage, and a plurality of fourthpads transmitting a second power voltage different from the first powervoltage, within a display area; and a plurality of display modules, eachof which includes first to fourth bonding electrodes attached to thefirst to fourth pads, a first transistor connected to the first bondingelectrode and the second bonding electrode, a second transistorconnected to the third bonding electrode, and a light emitting diodeconnected to the second transistor and the fourth bonding electrode. 2.The display device of claim 1, wherein: the substrate further includes aplurality of gate lines and a plurality of second power voltage linesextended in a first direction and arranged in a second directioncrossing the first direction, and a plurality of data lines and aplurality of first power voltage lines extended in the second directionand arranged in the first direction, and the plurality of first pads isconnected to the plurality of gate lines, the plurality of second padsis connected to the plurality of data lines, the plurality of third padsis connected to the plurality of first power voltage lines, and theplurality of fourth pads is connected to the plurality of second powervoltage lines.
 3. The display device of claim 2, wherein: the pluralityof display modules is arranged in a matrix form in the first directionand the second direction, and at least one of the plurality of displaymodules is arranged to be shifted in a column direction or a rowdirection. display device.
 4. The display device of claim 3, wherein: atleast one of the plurality of display modules connected to the firstdata line among the plurality of data lines is connected to a firstpower voltage line different from first power voltage lines of otherdisplay modules.
 5. The display device of claim 3, wherein: at least oneof the plurality of display modules connected to a first gate line amongthe plurality of gate lines is connected to a second power voltage linedifferent from second power voltage lines of other display modules. 6.The display device of claim 2, wherein: the plurality of display modulesincludes a plurality of first display modules each of which includes aplurality of light emitting diodes, and a plurality of second displaymodules each of which includes one light emitting diode.
 7. The displaydevice of claim 6, wherein: in the plurality of first display modules,the plurality of light emitting diodes is arranged in different forms.8. The display device of claim 2, wherein: the plurality of gate linesand the plurality of second power voltage lines, and the plurality ofdata lines and the plurality of first power voltage lines are located ondifferent layers.
 9. The display device of claim 1, wherein: the displayarea has a non-quadrangular form.
 10. The display device of claim 1,wherein: the substrate has a curved form.
 11. The display device ofclaim 10, wherein: the substrate includes at least one of a front glass,a rear glass, and side mirrors of a vehicle.
 12. The display device ofclaim 1, further comprising: a curved glass substrate, wherein thesubstrate is flexible, and the substrate is attached to the glasssubstrate.
 13. The display device of claim 12, wherein: the substrateincludes at least one of a front glass, a rear glass, and side mirrorsof a vehicle.
 14. The display device of claim 1, further comprising: agate driving unit supplying the gate signal and a source driving unitsupplying the data signal, the gate driving unit and the source drivingunit being disposed in a bezel area.
 15. The display device of claim 1,wherein each of the plurality of display modules further includes: adisplay element including a substrate, a first conductive semiconductorlayer on the substrate, a first electrode on the first conductivesemiconductor layer, a first activation layer on the first conductivesemiconductor layer, a second conductive semiconductor layer on thefirst activation layer, a reflective layer on the second conductivesemiconductor layer, a first passivation layer covering the reflectivelayer, a first electrode connected to the first conductive semiconductorlayer and located on the first passivation layer, and a second electrodeconnected to the reflective layer and located on the passivation layer,in which the light emitting diode includes the first conductivesemiconductor layer, the first activation layer, and the secondconductive semiconductor layer; and a transistor including a first gateelectrode on the first passivation layer, a gate insulating layer on thefirst gate electrode, a second activation layer on the gate insulatinglayer, a source electrode and a drain electrode on the second activationlayer, a second passivation layer covering the source electrode and thedrain electrode, and a second gate electrode on the second passivationlayer, and wherein the first bonding electrode is connected to the firstelectrode, the second bonding electrode is connected to the drainelectrode, and the second electrode is connected to the sourceelectrode.
 16. A display device, comprising: a display element includinga substrate, a first conductive semiconductor layer on the substrate, afirst electrode on the first conductive semiconductor layer, a firstactivation layer on the first conductive semiconductor layer, a secondconductive semiconductor layer on the first activation layer, areflective layer on the second conductive semiconductor layer, a firstpassivation layer covering the reflective layer, a first electrodeconnected to the first conductive semiconductor layer and located on thefirst passivation layer, and a second electrode connected to thereflective layer and located on the passivation layer, a transistorincluding a first gate electrode on the first passivation layer, a gateinsulating layer on the first gate electrode, a second activation layeron the gate insulating layer, a source electrode and a drain electrodeon the second activation layer, a second passivation layer covering thesource electrode and the drain electrode, and a second gate electrode onthe second passivation layer; and a first bonding electrode connected tothe first electrode and a second bonding electrode connected to thedrain electrode, wherein the second electrode is connected to the sourceelectrode.
 17. The display device of claim 16, wherein: the firstconductive semiconductor layer and the second conductive semiconductorlayer are formed of an III-V group material.
 18. The display device ofclaim 16, wherein: the first activation layer is formed of an III-Vgroup material.
 19. The display device of claim 16, wherein: at leastone of the first electrode, the second electrode, the first gateelectrode, the source electrode, the drain electrode, the second gateelectrode, the first bonding electrode, and the second bonding electrodeincludes at least one transparent material of an indium tin oxide (ITO),an indium zinc oxide (IZO), and an Ag nanowire.
 20. A method ofmanufacturing a display device, the method comprising: forming a firstconductive semiconductor layer on a substrate; forming a firstactivation layer on the first conductive semiconductor layer; forming asecond conductive semiconductor layer on the first activation layer;forming a light emitting diode by forming a reflective layer on thesecond conductive semiconductor layer; forming a first passivation layercovering the reflective layer; forming a first electrode connected tothe first conductive semiconductor layer on the first passivation layerand a second electrode and a first gate electrode connected to thereflective layer; forming a gate insulating layer on the first gateelectrode; forming a second activation layer on the gate insulatinglayer; forming a drain electrode and a source electrode connected to thesecond electrode on the second activation layer; forming a secondpassivation layer covering the source electrode and the drain electrode;forming a transistor by forming a second gate electrode on the secondpassivation layer; forming a third passivation layer on the second gateelectrode; forming a first bonding electrode connected to the firstelectrode and a second bonding electrode connected to the drainelectrode on the third passivation layer; cutting the substrate on whichthe light emitting diode and the transistor are formed into a pluralityof display modules; and attaching the display module to the substrateincluding a plurality of pads to which a signal used for the lightemitting diode to emit light is applied.